Resolution gas recycling device

Abstract

The utility model relates to the field of synthesis ammonia and industrial hydrogen production, and particularly provides a desorbed gas recycling device which comprises a shift gas absorption tower, a pressure swing adsorption tower, a desorbed gas compressor, a shift converter, a hydrogen-rich torch and a torch incandescent light, an inlet end of the converted gas absorption tower is connected with a converted gas outlet pipe, a converted gas outlet pipe is connected with the conversion furnace, an outlet end of the converted gas absorption tower is connected with a purified gas outlet pipe, the purified gas outlet pipe is connected with the pressure swing adsorption tower through a purified gas branch pipe, and an outlet end of the pressure swing adsorption tower is connected with a hydrogen delivery pipe and an analysis gas header pipe; one end of the desorbed gas header pipe is connected with a desorbed gas compressor through a desorbed gas inlet pipe, and the other end is connected with a hydrogen-rich torch and a torch incandescent light; the desorption gas compressor is connected with the conversion furnace through a conversion gas inlet pipe, the inlet end of the torch incandescent light is connected with a torch LPG pipe, and LPG enters the torch incandescent light through the torch LPG pipe. Compared with the prior art, the device has the advantages that the cost can be saved, and the cyclic utilization of the desorption gas is realized.

Description

Technical Field

[0001] The utility model relates to the technical field of synthetic ammonia and industrial hydrogen production, and specifically provides a device for recycling and utilizing purge gas. Background Art

[0002] Hydrogen has a wide range of applications in the chemical industry. It is an essential raw material and intermediate in chemical production and can be used as a reducing agent, hydrogenating agent, oxidizing agent, fuel, catalyst, etc. In the field of synthetic ammonia production, hydrogen is a common by-product, and the PSA hydrogen production process is often used to produce hydrogen as a by-product for external sales. The purge gas generated during the production of hydrogen is usually discharged to the flare for combustion. Since the hydrogen content in the purge gas is relatively high, with a volume content of over 80%, direct discharge causes serious waste.

[0003] To effectively solve the above problems, the utility model provides a device for recycling and utilizing purge gas, and its main purpose is to recover the effective components of hydrogen and carbon monoxide in the purge gas and realize the recycling of the purge gas. Summary of the Invention

[0004] The utility model aims at the above-mentioned deficiencies of the prior art and provides a device for recycling and utilizing purge gas with reasonable design and safe use.

[0005] The technical solution adopted by the utility model to solve its technical problems is as follows:

[0006] A device for recycling and utilizing purge gas includes a shift gas absorption tower, a pressure swing adsorption tower, a purge gas compressor, a shift furnace, a hydrogen-rich flare, and a flare pilot light.

[0007] The inlet end of the shift gas absorption tower is connected to the shift gas outlet pipe, and the shift gas outlet pipe is connected to the shift furnace.

[0008] The outlet end of the shift gas absorption tower is connected to the purified gas outlet pipe, and the purified gas outlet pipe is connected to the pressure swing adsorption tower through a purified gas branch pipe. The outlet end of the pressure swing adsorption tower is connected to the hydrogen external delivery pipe and the purge gas main pipe. One end of the purge gas main pipe is connected to the purge gas compressor through a purge gas inlet pipe, and the other end is connected to a hydrogen-rich flare and a flare pilot light.

[0009] The purge gas compressor is connected to the shift furnace through a shift gas inlet pipe. The hydrogen-rich flare ensures safety under abnormal conditions of the device. The inlet end of the flare pilot light is connected to a flare LPG pipe, and LPG enters the flare pilot light through the flare LPG pipe to keep the flare pilot light burning continuously.

[0010] Further, the purge gas compressor is connected to the shift gas inlet pipe through a purge gas outlet pipe, and the shift gas inlet pipe is connected to the shift furnace.

[0011] Further, the analytical gas main pipe is connected to the hydrogen-rich flare through the analytical gas safety valve inlet pipe and the hydrogen-rich flare pipe, and a safety valve I is provided on the analytical gas safety valve inlet pipe.

[0012] Further, the analytical gas main pipe is connected with an analytical gas branch pipe, and the analytical gas branch pipe is connected to the flare LPG pipe.

[0013] Further, a compressor inlet valve is provided on the analytical gas inlet pipe, a compressor outlet valve is provided on the analytical gas outlet pipe, and a compressor safety valve inlet pipe is connected thereto. The compressor safety valve inlet pipe is connected to the hydrogen-rich flare pipe through a compressor safety valve outlet pipe, and a safety valve II is provided on the compressor safety valve inlet pipe.

[0014] Further, an emergency cut-off valve, an automatic regulating valve and a pressure transmitter are provided on the purified gas branch pipe. The pressure transmitter is provided with low-pressure, high-pressure and ultra-high-pressure alarm functions and a remote transmission function, and is displayed and monitored on the DCS system.

[0015] At the same time, the pressure transmitter, the emergency cut-off valve and the automatic regulating valve are set as an interlocking loop.

[0016] Preferably, the model of the pressure transmitter is EJA530E-JCS7-3CDL / NS21.

[0017] Compared with the prior art, an analytical gas recovery and utilization device of the present utility model has the following prominent beneficial effects:

[0018] The analytical gas of the present utility model is recovered to the inlet of the conversion furnace, and the effective gases such as hydrogen and carbon monoxide in the analytical gas are recovered and utilized, increasing the production of liquid ammonia. The analytical gas is used instead of LPG for the pilot light of the flare, reducing the consumption of LPG and lowering the production cost. Under abnormal conditions, the analytical gas can be vented to the hydrogen-rich flare, ensuring the safe and stable operation of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0020] Attached Figure 1 is a structural schematic diagram of an analytical gas recovery and utilization device.

[0021] The marks in the drawings respectively represent:

[0022] 1. Shift gas absorption tower, 2. Pressure swing adsorption tower, 3. Analytic gas compressor, 4. Converter, 5. Hydrogen-rich torch, 6. Torch pilot light, 7. Shift gas outlet pipe, 8. Purified gas branch pipe, 9. Analytic gas main pipe, 10. Analytic gas inlet pipe, 11. Analytic gas branch pipe, 12. Analytic gas safety valve inlet pipe, 13. Hydrogen-rich torch pipe, 14. Analytic gas outlet pipe, 15. Shift gas inlet pipe, 16. Compressor safety valve inlet pipe, 17. Compressor safety valve outlet pipe, 18. Emergency cut-off pipe, 19. Automatic regulating valve, 20. Safety valve I, 21. Safety valve II, 22. Compressor inlet valve, 23. Compressor outlet valve, 24. Pressure transmitter, 25. Torch LPG pipe, 26. Purified gas outlet pipe, 27. Hydrogen external delivery pipe. Detailed implementation mode

[0023] The present utility model will be further described below in conjunction with the accompanying drawings and specific embodiments, but it is not limited to the present utility model.

[0024] In the present utility model, unless otherwise specified, the orientation words such as "upper, lower, left, right" usually refer to the upper, lower, left, and right shown in the reference drawings; "inside and outside" refer to the inside and outside relative to the contour of each component itself.

[0025] The following gives an optimal embodiment:

[0026] As Figure 1 shown, an analytic gas recycling device in this embodiment includes a shift gas absorption tower 1, a pressure swing adsorption tower 2, an analytic gas compressor 3, a converter 4, a hydrogen-rich torch 5 and a torch pilot light 6;

[0027] Among them, the inlet end of the shift gas absorption tower 1 is connected to the shift gas outlet pipe 7, and the shift gas outlet pipe 7 is connected to the converter 4;

[0028] The outlet end of the shift gas absorption tower 1 is connected to the purified gas outlet pipe 26, the purified gas outlet pipe 26 is connected to the pressure swing adsorption tower 2 through the purified gas branch pipe 8, the outlet end of the pressure swing adsorption tower 2 is connected to the hydrogen external delivery pipe 27 and the analytic gas main pipe 9, one end of the analytic gas main pipe 9 is connected to the analytic gas compressor 3 through the analytic gas inlet pipe 10, and the other end is connected to a hydrogen-rich torch 5 and a torch pilot light 6;

[0029] The analytic gas compressor 3 in this embodiment is connected to the shift gas inlet pipe 15 through the analytic gas outlet pipe 14, and the shift gas inlet pipe 15 is connected to the converter 4. The hydrogen-rich torch 5 ensures safety under abnormal conditions of the device. The inlet end of the torch pilot light 6 is connected to a torch LPG pipe 25, and LPG enters the torch pilot light 6 through the torch LPG pipe 25 to keep the torch pilot light 6 burning continuously.

[0030] The analytic gas compressor 3 in this embodiment is connected to the shift gas inlet pipe 15 through the analytic gas outlet pipe 14, and the shift gas inlet pipe 15 is connected to the converter 4.

[0031] The analytical gas main pipe 9 is successively connected to the hydrogen-rich flare 5 through the analytical gas safety valve inlet pipe 12 and the hydrogen-rich flare pipe 13. A safety valve I 20 is also provided on the analytical gas safety valve inlet pipe 12.

[0032] The analytical gas main pipe 9 is connected with an analytical gas branch pipe 11, and the analytical gas branch pipe 11 is connected to the flare LPG pipe 25.

[0033] A compressor inlet valve 22 is provided on the analytical gas inlet pipe 10. A compressor outlet valve 23 is provided on the analytical gas outlet pipe 14 and is connected with a compressor safety valve inlet pipe 16. The compressor safety valve inlet pipe 16 is connected to the hydrogen-rich flare pipe 13 through a compressor safety valve outlet pipe 17, and a safety valve II 21 is provided on the compressor safety valve inlet pipe 16.

[0034] Among them, an emergency cut-off valve 18, an automatic regulating valve 19 and a pressure transmitter 24 are provided on the purified gas branch pipe 8. The pressure transmitter 24 is provided with low-pressure, high-pressure and ultra-high-pressure alarm functions and a remote transmission function, and is displayed and monitored on the DCS system. Among them, the model of the pressure transmitter 24 is EJA530E-JCS7-3CDL / NS21.

[0035] At the same time, the pressure transmitter 24, the emergency cut-off valve 18 and the automatic regulating valve 19 are set as an interlocking loop.

[0036] When the analytical gas recycling device in this embodiment is in use, the inlet end of the shift gas absorption tower 1 is connected to the shift gas outlet pipe 7, and the outlet end is connected to the purified gas outlet pipe 26. In the current synthetic ammonia production process, the shift gas produced by the shift furnace 4 enters the shift gas absorption tower 1 through the shift gas outlet pipe 7. The shift gas is purified in the shift gas absorption tower 1, and after removing impurity components such as H2S, COS and CO2 in the shift gas, it becomes purified gas and is led out from the top of the tower. The H2 content in the purified gas out of the shift gas absorption tower can be as high as 97%. This part of the gas can be used as the raw material gas for producing synthetic ammonia and is sent to the downstream section to produce liquid ammonia through the purified gas outlet pipe 26.

[0037] At the same time, this part of the purified gas can also be used as the raw material gas for producing industrial hydrogen. Through the purified gas branch pipe 8, it enters the pressure swing adsorption tower 2 to produce industrial hydrogen in a pipeline transportation manner.

[0038] The inlet end of the pressure swing adsorption tower 2 is connected to the purified gas branch pipe 8, and the outlet end is connected to the hydrogen delivery pipe 27 and the desorption gas main pipe 9. In the pressure swing adsorption tower 2, the purified gas from the conversion gas absorption tower 1 is purified by the PSA pressure swing adsorption process to produce qualified product hydrogen with a hydrogen content greater than 99.9%, which is transported to the outside through the hydrogen delivery pipe 27 for sale or use. The waste gas generated in the pressure swing adsorption process, i.e., the desorption gas, has a hydrogen content of up to 89% and a pressure of 0.03MPa, and is transported to the desorption gas compressor, hydrogen-rich torch or torch permanent lamp through the desorption gas main pipe 9.

[0039] The inlet end of the desorption gas compressor 3 is connected to the desorption gas inlet pipe 10, and the outlet end is connected to the desorption gas outlet pipe 14. The desorption gas is pressurized by the desorption gas compressor 3, and the pressure is increased from 0.03MPa to 6.2MPa, and then connected to the conversion gas inlet pipe 15 through the desorption gas outlet pipe 14, and is recycled as the raw gas of the conversion furnace.

[0040] The inlet end of the shift furnace 4 is connected to the shift gas inlet pipe 15, and the outlet end is connected to the shift gas outlet pipe 7. The shift gas produced by the gasifier in the synthetic ammonia process enters the shift furnace 4 through the shift gas inlet pipe 15, and a shift reaction occurs in the shift furnace 4 to produce a purified gas with a CO dry content of no more than 0.6% and trace impurity components such as H2S, COS and CO2, and enters the shift gas absorption tower 1 through the shift gas outlet pipe 7.

[0041] The inlet end of the torch pilot light 6 is connected to the torch LPG pipe 25. In the production of synthetic ammonia plant, the torch pilot light generally uses LPG as fuel, and LPG enters the torch pilot light through the torch LPG pipe 25 to keep the torch pilot light burning continuously.

[0042] After the analytical gas is pressurized by the analytical gas compressor, it is connected to the conversion gas inlet pipe 15 through the analytical gas outlet pipe 14, mixed with the conversion gas, and enters the conversion furnace 4 through the conversion gas inlet pipe to be recycled as the raw gas of the conversion furnace.

[0043] A safety valve I20 is provided on the desorption gas main pipe 9. If the desorption gas compressor 3 fails, or the compressor inlet valve 22 fails, or other abnormal conditions occur, the pressure between the pressure swing adsorption tower 2 and the desorption gas compressor 3 is blocked, and the safety valve I20 is tripped, and the desorption gas can be discharged to the hydrogen-rich flare 5 through the hydrogen-rich flare pipe 13 to ensure the safety of the pressure swing adsorption tower.

[0044] The desorbed gas main pipe 9 is provided with a desorbed gas branch pipe 11. Since the hydrogen content in the desorbed gas is high and it can be used as the fuel for the torch pilot burner instead of LPG, the desorbed gas can be connected to the torch LPG pipe 25 through the desorbed gas branch pipe 11 and used as the fuel for the torch pilot burner instead of LPG. Since the price of LPG is relatively high, the long-term operation cost of the device is high. Using this device can save the procurement cost of LPG and reduce the operation cost of the torch device.

[0045] A compressor inlet valve 22 and a compressor outlet valve 23 are provided at the inlet and outlet ends of the desorbed gas compressor 3; if a failure occurs in the desorbed gas compressor equipment or the compressor outlet valve 23 fails, the system is blocked by pressure, and the safety valve II 21 jumps. The desorbed gas can be connected to the hydrogen-rich torch pipe 13 through the compressor safety valve outlet pipe 17 and discharged to the hydrogen-rich torch.

[0046] An emergency cut-off valve 18, an automatic regulating valve 19, and a pressure transmitter 24 are provided on the purified gas branch pipe 8. The pressure transmitter 24 is provided with low-pressure, high-pressure, and very high-pressure alarm functions and a remote transmission function, and is displayed and monitored on the DCS system.

[0047] At the same time, an interlock circuit is set between the pressure transmitter 24, the emergency cut-off valve 18, and the automatic regulating valve 19. Under normal operating conditions, the emergency cut-off valve 18 is in the open state, and the automatic regulating valve automatically adjusts the valve opening according to the pressure value of the pressure transmitter 24 to control the system pressure to be in a stable state.

[0048] If a failure occurs in the system, when the value of the pressure transmitter 24 reaches the set value of the very high alarm, the emergency cut-off valve 18 is interlocked and closed, cutting off the pressure swing adsorption tower 2 and the subsequent processes to ensure the safety of the system. All the purified gas enters the subsequent processes of synthetic ammonia production through the purified gas outlet pipe 26.

[0049] The above-described embodiments are only one of the more preferred specific embodiments of the present invention. The common changes and substitutions made by those skilled in the art within the scope of the technical solution of the present invention should be included in the protection scope of the present invention.

Claims

1. A desorption gas recovery and utilization device, characterized in that: It includes a shift gas absorption tower, a pressure swing adsorption tower, a desorption gas compressor, a shift furnace, a hydrogen-rich flare and a flare permanent lamp; The inlet end of the conversion gas absorption tower is connected to the conversion gas outlet pipe, and the conversion gas outlet pipe is connected to the conversion furnace. The outlet end of the conversion gas absorption tower is connected to the purified gas outlet pipe, the purified gas outlet pipe is connected to the pressure swing adsorption tower through the purified gas branch pipe, the outlet end of the pressure swing adsorption tower is connected to the hydrogen delivery pipe and the desorption gas main pipe, one end of the desorption gas main pipe is connected to the desorption gas compressor through the desorption gas inlet pipe, and the other end is connected to the hydrogen-rich flare and the flare permanent lamp; The analytical gas compressor is connected to the conversion furnace through a conversion gas inlet pipe. The hydrogen-rich flare ensures safety in abnormal conditions of the device. The inlet end of the flare pilot light is connected to a flare LPG pipe. LPG enters the flare pilot light through the flare LPG pipe to keep the flare pilot light burning continuously.

2. The analytical gas recovery and utilization device according to claim 1, characterized in that: The analytical gas compressor is connected to the conversion gas inlet pipe through the analytical gas outlet pipe, and the conversion gas inlet pipe is connected to the conversion furnace.

3. The analytical gas recovery and utilization device according to claim 2, characterized in that: The analytical gas main pipe is connected to the hydrogen-rich torch through an analytical gas safety valve inlet pipe and a hydrogen-rich torch pipe, and a safety valve I is arranged on the analytical gas safety valve inlet pipe.

4. The analytical gas recovery and utilization device according to claim 3, characterized in that: The analytical gas main pipe is connected with an analytical gas branch pipe, and the analytical gas branch pipe is connected with the flare LPG pipe.

5. The analytical gas recovery and utilization device according to claim 4, characterized in that: The analytical gas inlet pipe is provided with a compressor inlet valve, the analytical gas outlet pipe is provided with a compressor outlet valve and is connected to a compressor safety valve inlet pipe, the compressor safety valve inlet pipe is connected to the hydrogen-rich flare pipe through the compressor safety valve outlet pipe, and a safety valve II is provided on the compressor safety valve inlet pipe.

6. The analytical gas recovery and utilization device according to claim 4, characterized in that: The purified gas branch pipe is provided with an emergency shut-off valve, an automatic regulating valve and a pressure transmitter. The pressure transmitter is provided with low pressure, high pressure and high pressure alarm functions and a remote transmission function, and is displayed and monitored on the DCS system. At the same time, the pressure transmitter, the emergency shut-off valve and the automatic regulating valve are arranged as an interlocking circuit.

7. The analytical gas recovery and utilization device according to claim 6, characterized in that: The model of the pressure transmitter is EJA530E-JCS7-3CDL / NS21.

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